The studio who made the first two games felt like the story was wrapped up pretty nicely and wanted to try their hand at something else even despite being offered a contract for the third game by Microsoft... at least that's what I heard :\
I hope I am wrong tho, I really want to see more stuff set in this universe seeing as both games are phenomenal, even if the ending of the second one made me a bit annoyed.
The studio who made the first two games felt like the story was wrapped up pretty nicely and wanted